(P27-055-24) Eggshell Membrane Modulates the Gut Microbiota to Provide Health-Promoting Benefits

Objectives: Eggshell membrane (ESM) is a fibrous structure between eggshell and egg white, and it is considered a resistant protein due to its low digestibility (approximately 46%) in the mammalian’s digestive system, which reward prebiotic-like properties. ESM's enteric fermentation positively affects the gut microbiota composition, leading to remarkable health benefits, including anti-inflammatory effect in inflammatory bowel disease, lipid-lowering activity, suppression of T-helper cell differentiation in murine pre-cachexia, and amelioration of gut dysbiosis in interleukin-10 knockout mice. Given that gut dysbiosis is closely linked to age-related inflammation and chronic diseases, the objective of this research was to investigate the potential effects of ESM on age-related inflammation and aging markers in naturally aging mice.

Methods: Male C57BL/6J mice aged 53 weeks received a six-month 8% ESM diet intervention, while the control group received a basic diet. Assessments included plasma and hepatic lipid profiles, forelimb grip strength tests, gut microbiota composition analysis, mRNA expression analysis of aging-related genes and pro-inflammatory cytokines in the liver, colonic mucosa, and brain hippocampus, and organic acids analysis from mouse cecal content.

Results: ESM group exhibited improved body leanness, with reduced intraperitoneal fat content and increased gastrocnemius muscle weight. Forelimb grip strength was notably enhanced in the ESM group, and hepatic p16INK4A and Il6 expression in the brain hippocampus was significantly downregulated. Furthermore, ESM diet distinctively lowered the abundance of obesity- and inflammation-related bacteria and pathogenic bacteria, while enriching preferrable butyrate-producing and valerate-producing bacteria. Additionally, ESM diet significantly promoted the production of iso-butyrate, iso-valerate, and valerate.

Conclusions: Our data provide insight into the significant roles of ESM in modulating the gut microbiota composition, producing anti-inflammatory fermentation metabolite, and preventing fat accumulation, all of which may potentially suppress age-related inflammation.

Funding Sources: This work was funded by a Grant-in-Aid from the Japan Society for the Promotion of Science.